The two quality assurance (QA) objectives of positioning and dosimetric accuracy currently require multiple phantom setups for radiation therapy before patient get treated or the periodic QA to ensure performance of the system. Various localization and positioning systems with the use of radiographic or non-radiographic methods have been developed to improve the accuracy of radiation treatment. Dose measurement was usually performed independently. However, there is no single integrated phantom that can be used for QA for all systems, as well as dose measurements. Each QA procedure requires its own phantom and is independent from each other, so the deviation between each system is unavailable.
With escalated doses and decreased margin for radiation therapy treatment, a positioning system with higher accuracy is essential, as well as dose measurements. In order to deliver the dose precisely, several localization techniques have been developed for positioning the patients so the treatment can be delivered with precision and efficiency. Those techniques are used before and/or during the treatment to setup and monitor patient position. There are two categories, which are radiographic and non-radiographic radiotherapy localization and positioning systems. For radiographic system, it includes kV/MV portal images, cone beam computed tomography (CBCT) and Winston-Lutz test to verify the radiation isocenter. For non-radiographic system, it includes optical surface monitoring system, a 3D imaging technology that provides high resolution and accurate 3D surface data referenced to the treatment isocenter, and radiofrequency (RF) beacon tracking system, a tracking device using RF waves to localize the target. Each localization system requires periodic measurements of specified parameters to ensure that hardware and software functions safely and reliably perform as expected. Each quality assurance (QA) needs its own procedure and phantom and the deviation between each system is unavailable. It is time consuming to setup the QA phantom and to perform the QA procedure for each system. The reproducibility of the phantom setup is dependent the QA physicist. The space to store the QA phantoms can grow very quickly with the number of phantoms required for the QA. Moreover, the QA phantoms for RF tracking and optical surface monitoring systems are provided by the manufacture, which leads to self-QA and it is not an independent check from the vendor. There are few phantoms that were developed for each technique but none of them can do the QA for all systems.
What is needed is a method and device that combines the QA tests into a single phantom, to have an independent QA method from the vendor, to reduce the number of phantoms required for QA, to reduce the time required of the medical physicist to perform these QA tasks, and to increase the reproducibility of phantom placement to evaluate the deviation of isocenter between the individual systems.